Hewlett-Packard has new entry in desk-top calculator market

Programable desk-top calculators that give computational capability ap­proaching that of full-scale computers in a package the size of a typewriter continue to interest both user and maker alike. Latest offering is Hew­lett-Packard's Model 9100A shown at the International Convention and Ex­hibition of the Institute of Electrical and Electronics Engineers, New York.

The Model 9100A calculator is de­signed particularly for the fast-growing market for machines intermediate be­tween calculators and computers—a total market which Hewlett-Packard chairman David Packard estimates at $25 million annually. The instrument can run programs as well as solve transcendental functions, making it valuable for handling scientific and en­gineering problems. Hewlett-Pack­ard's Dr. Bernard M. Oliver, vice president of research and develop­ment, comments: "We hope to see this calculator everywhere there are slide rules."

This relatively new market opened up in late 1965 when Olivetti Under­wood began producing its desk-top Programma 101 computer ($3850) and Wang Laboratories, Inc., began producing its 300-series of desk-top keyboard consoles with separate elec­tronics packages ($3795). To date, Olivetti says it has sold about 2900 of its Programma 101 computers.

Hewlett-Packard's $4900 minicom­puter has programing and memory capabilities and performs arithmetic, logarithmic, trigonometric, hyperbolic, and coordinate transformation opera­tions in milliseconds. The calculator thus can solve such scientific and en­gineering problems as regression anal­yses, transcendental equations (three-dimensional vectors), numerical in­tegration, and differential equations.

Some Wulff process troubles relate to scaleup, startup

Details of the problems plaguing plants in Europe using the Wulff acet­ylene process were revealed last week by Union Carbide's P. E. Boliek at the Dechema-Society of Chemical Indus­try conference on acetylene or ethyl­ene as raw materials, held in Frank­furt/Main, West Germany. Late and sporadic startup of large Wulff plants in Europe is fairly common knowledge (C&EN, Feb. 5, page 37). But up to now little has been said about the spe­cific problems.

Some of these, it is now apparent, relate simply to scaleup and startup.

For example, there have been failures in plant interlock systems. Also, in the U.K., smooth operation of the combus­tion furnaces has been plagued by in­accurate metering. Another problem has been failure in furnace linings, Mr. Boliek says. Successful use of high-grade alumina as a refractory furnace lining indicates purity is important.

Problems more specific to the Wulff process are related to combustion char­acteristics. Basically, the process is based on a one-minute, four-stroke cy­cle using twin regenerative furnaces. While combustion takes place in one furnace, the other undergoes carbon deposit burnoff, purging, and warmup. Originally, the four-way switching valves that accommodate furnace inlet and outlet gases in the cycle stuck from time to time. One reason is a large temperature gradient of up to several hundred degrees Centigrade across the valve. Now, Mr. Boliek says, they operate satisfactorily with proper clearance that allows lubrication.

Earlier problems arising from un-homogeneous heat release during com­bustion have been largely overcome by inlet nozzle changes. Precisely con­trolled fuel- and air-feed rates and a dual nozzle system give uniform heat release. Excessive fuel nozzle loss was a problem of U.K. plants, Mr. Boliek says, but this has been rectified by adding a steam purge.

Waste industrial heat key to new Alcoa desalination system

A new water desalination system de­signed to take advantage of waste in­dustrial heat has been developed by Aluminum Co. of America. The sys­tem uses all-aluminum construction, has a simple design concept, and oper­ates at much lower temperatures than do other desalination systems based on distillation. These characteristics make possible much lower purification costs than other large-scale desalination methods, Alcoa claims.

The new system, worked out by Dr. Melvin H. Brown at Alcoa's new Ken­sington, Pa., research laboratories, will produce fresh water at a third to half the cost for plants now operating or under construction, according to Alcoa calculations. The aluminum compo­nents are much less expensive than the usual stainless steel, cupro-nickel, or titanium components.

The new system uses waste hot wa­ter available at chemical plants, refin­eries, fertilizer plants, and steam-pow­ered electric generating plants. It can also use sun-warmed sea water, since it can operate with a temperature dif­ference as small as 20° F. The system is not meant to compete with desalina-

Prototype of Alcoa's desalting plant Lower operating costs

tion systems which include their own energy source, such as steam nuclear-powered distillation plants. Alcoa foresees wide use for the system in areas where clean water is needed and waste heat is plentiful.

Alcoa is now planning a prototype plant using the new system, but its lo­cation hasn't yet been determined. The plant's first stage, which will have a capacity of 250,000 gallons of fresh water per day, will be built within the next 18 months. The process is readily adaptable to unit construction, Alcoa says, so several of these 250,000 gal-lon-per-day units could be coupled to make multimillion-gallon plants.

Lower operating temperatures mean lower initial and maintenance costs. (Distillation desalination processes now use temperatures as high as 200° to 250° F.) Since the system operates on waste heat, fuel costs (which nor­mally make up 40 to 50% of the cost of water desalinated by distillation processes) will be greatly reduced. Alcoa estimates it will cost 25 to 50 cents to make a thousand gallons of fresh water using its system, in con­trast with 85 cents to $1.00 per thou­sand gallons for conventional desalina­tion systems producing 1 million to 5 million gallons per day by distillation.

Alcoa's system also uses a flash dis­tillation process, and it takes advan­tage of the temperature difference be­tween streams of hot and cold water. The company has applied for a patent on the system and, therefore, won't disclose any details yet.

In its processing of waste hot water, the system partially cools the water. Thus it can help reduce thermal pol­lution from hot waste water dis­charged directly into the environment.

APRIL 1, 1968 C&EN 13